Download or read book Silurian Wenlock Demosponges from the Avalanche Lake Area of the Mackenzie Mountains Southwestern District of Mackenzie Northwest Territories Canada written by J. Keith Rigby and published by . This book was released on 1983 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A New Silurian Llandovery Telychian Sponge Assemblage from Gotland Sweden written by Freek Rhebergen and published by John Wiley & Sons. This book was released on 2014-02-27 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: A newly discovered, diverse sponge fauna of early Silurian age, is described from Gotland, Sweden. This is the first Silurian sponge assemblage known from Baltica, and the only diverse Llandoverian assemblage known worldwide. The fauna includes 20 genera and 29 species, of which three genera and six species are new. Eighteen species are new to Baltica. The fauna shows strong similarities to later Silurian assemblages in Arctic Canada, but one endemic species comprises ca. 50% of the fauna. The fauna shows that lithistid sponges recovered well from the late Ordovician extinction in some areas, and became widely spread in the early Silurian. In contrast, non-lithistid sponges like, such as hexactinellids, appear to have evolved rapidly during the Late Ordovician – early Silurian interval, and some modern groups probably originated in inshore habitats.
Download or read book Palaeontographica Canadiana written by and published by . This book was released on 1983 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Conference on the Cambrian Explosion written by Paul A. Johnston and published by . This book was released on 2011 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Silurian Devonian Sequence in the Northern Part of the Mackenzie Shelf Northwest Territories written by D. W. Morrow and published by . This book was released on 1991 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: This outline of the Silurian-Devonian stratigraphy of the Mackenzie Mountains, Northwest Territories, describes the tectonics of the region including the Redstone Arch.
Download or read book Oklahoma Geology Notes written by and published by . This book was released on 2009 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silurian Wenlock Ludlow encrinurine trilobites from the Mackenzie Mountains Canada and related species written by Gregory D. Edgecombe and published by . This book was released on 1993 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Palaeoclimatology and Palaeoceanography from Laminated Sediments written by Alan E. S. Kemp and published by Geological Society of London. This book was released on 1996 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: The magnitude and causes of decadal to century-scale changes in climate are major issues of global concern. The separation of anthropogenically driven change from natural 'baseline' variability within the atmosphere/ocean system is a prerequisite to identifying human impact on global climate. An understanding of past climate variability is therefore a key to predicting future climate change. The sedimentary record of the oceans, seas and lakes is produced by a series of depositional events that occur on seasonal timescales but can rarely be resolved due to mixing of the sediment by bottomdwelling organisms. Where they are preserved, laminated sediments act like tree rings to record these seasonal-scale processes, such as plankton blooms and floods, and provide a uniquely high-resolution record of environmental change. In addition, annually laminated or 'varved' sediment sequences act as geochronometers against which other timescales can be tested. Laminated sediments may therefore be used to develop records of interannual and decadal-scale variability which serve to test models of climate change. The authors cover a range of topics that include strategies for study and techniques of analysis. A series of case studies, dealing with a variety of lacustrine and marine records, illustrates the wide potential of laminated sediments as palaeoclimatic and palaeoceanographic indicators.
Download or read book Quaternary Vegetation Dynamics written by Jürgen Runge and published by CRC Press. This book was released on 2021-11-28 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book celebrates the relaunch of the African Pollen Database, presents state-of-the-art of modern and ancient pollen data from sub-Saharan Africa, and promotes Open Access science. Pollen grains are powerful tools for the study of past vegetation dynamics because they preserve well within sedimentary deposits and have a huge diversity in ornamentation that allows different taxa to be determined. The reconstruction of past vegetation from the examination of ancient pollen records thus can be used to characterize the nature of past landscapes (e.g. abundance of forests vs. grasslands), provide insights into changes in biodiversity, and gain empirical evidence of vegetation response to climatic change and human activity. In this, the 35th Volume of "Palaeoecology of Africa", we bring together new data and extensive synthetic reviews to provide novel insights into the relationships between human evolution, human activity, climate change and vegetation dynamics during the Quaternary, the last 2.6 million years. Current and ongoing climate and land-use change is exerting pressure on modern vegetation formations and threatening the livelihoods and wellbeing of many peoples in Africa. In this book the focus is on the Quaternary because it is during this geological period that the modern vegetation formations developed into their current configurations against a backdrop of high magnitude global climate change (glacial-interglacial cycles), human evolution, and a growing human land-use footprint. In this book the latest information is presented and collated from around the African continent to parameterize past vegetation states, identify the drivers of vegetation change, and assess the vegetation resilience to change. To achieve this research from two broad themes are covered: (i) the present is the key to the past (i.e. studies which improve our understanding of modern environments so that we can better interpret evidence from the past), and (ii) the past is the key to the future (i.e. studies which unlock information on how and why vegetation changed in the past so one can better anticipate trajectories of future change). This Open Access book will provide a strong foundation for future research exploring past ecological, environmental and climatic change within Africa and the surrounding islands. The book is organized regionally (covering western, eastern, central, and southern Africa) and it contains specialized articles focused on particular topics (such as modern pollen-vegetation relationships and fire as a driver of vegetation change), as well as regional and pan-African syntheses drawing together decades of research to assess key scientific questions (including the role of climate in driving vegetation change and the role of vegetation change in human evolution). These articles will be useful to students and teachers from high school to the highest level of university who are interested in the origins and dynamics of vegetation in Africa. Furthermore, it is also meant to provide societally relevant information that can act as an inspiration for the development of sustainable management practices for the future.
Download or read book Seismic Ground Motion In Large Urban Areas written by Giuliano F. Panza and published by Springer Science & Business Media. This book was released on 2004-04-23 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: The accelerated, and often uncontrolled, growth of the cities has contributed to the ecological transformation of their immediate surroundings. Factors contributing to the urban vulnerability include: lowering or rising of the water table, subsidence, loss of bearing capacity of soil foundations and instability of slopes. Recent catastrophic earthquakes highlight the poor understanding by decision makers of seismic related risk, as well as the tendency of some builders to use the cheapest designs and construction materials to increase short-term economic returns on their investment. Losses from earthquakes will continue to increase if we do not shift towards proactive solution. Disaster reduction is both an issue for consideration in the sustainable development agenda and a cross-cutting issue relating to the social, economic, environmental and humanitarian sectors. As location is the key factor, which determines the level of risk associated with a hazard, land-use plans and mapping should be used as tools to identify the most suitable usage for vulnerable areas.
Download or read book Silurian Reefs of Gotland written by and published by Elsevier. This book was released on 1971-01-01 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Swedish island of Gotland, in the Baltic, has attracted much attention of many geologists. Gotland is built up by a Middle Palaeozoic table-land, with an average height of 20-30 m, but with some higher hills in the inland and with steep cliffs along part of the coast. The Middle Palaeozoic strata consist primarily of limestones and marlstones. For a good understanding of the sedimentary succession of Gotland, it is important that the distribution of all the different kinds of sediments should be carefully mapped, and their faunal contents to be intensively studied. This book includes the survey and ideas gathered along with important data about the stratigraphy and reefs of Gotland. It presents description of the Baltic area, development of the stratigraphical subdivision of the Middle Palaeozoic of Gotland, and some tectonic and pseudo-tectonic phenomena. Stratified and unstratified sediments are presented along with a number of palaeoecological observations on Gotlandian fossils. Some comparisons of the reefs of Gotland with reefs in a few other areas are also examined.
Download or read book Late Eocene Zoogeography of the Eastern Gulf Coast Region written by Alan H. Cheetham and published by Geological Society of America. This book was released on 1963 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mineral Deposits written by Society for Geology Applied to Mineral Deposits. Meeting and published by Taylor & Francis. This book was released on 1995-01-01 with total page 1018 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains 253 extended abstracts presented at the third biennial SGA Meeting, held in Prague in 1995. The abstracts are grouped into topics, including metallogeny in the evolution of orogenic belts, gold and precious metal deposits, and metamorphism and mineralizations.
Download or read book Neogene Tonnoidean Gastropods of Tropical and South America written by A. G. Beu and published by . This book was released on 2010 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stratigraphy and Paleontology of the Permian Nosoni and Dekkas Formations Bollibokka Group written by Alan H. Coogan and published by . This book was released on 1960 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neogene Mollusks from Northwestern Ecuador written by Axel Adolf Olsson and published by . This book was released on 1964 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geology of Victoria written by John G. Douglas and published by . This book was released on 1993 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
